Converts ash to use aura-mus

ash/mus/bridge/wm_window_mus_test_api.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_MUS_BRIDGE_WM_WINDOW_MUS_TEST_API_H_
 #define ASH_MUS_BRIDGE_WM_WINDOW_MUS_TEST_API_H_
 
 #include "ash/mus/bridge/wm_window_mus.h"
 
 namespace ash {
 namespace mus {
 
 class WmWindowMusTestApi {
  public:
+  // Used by tests to set the default value of
+  // |WmWindowMus::default_use_empty_minimum_size_for_testing_|. This is needed
+  // as tests don't have a good way to reset the value of
+  // |use_empty_minimum_size_for_testing_| before the minimum size is queried.
+  class GlobalMinimumSizeLock {
+   public:
+    GlobalMinimumSizeLock();
+    ~GlobalMinimumSizeLock();
+
+   private:
+    // Number of instances of GlobalMinimumSizeLock that have been created.
+    static int instance_count_;
+
+    DISALLOW_COPY_AND_ASSIGN(GlobalMinimumSizeLock);
+  };
+
   explicit WmWindowMusTestApi(WmWindow* window)
       : WmWindowMusTestApi(WmWindowMus::AsWmWindowMus(window)) {}
   explicit WmWindowMusTestApi(WmWindowMus* window) : window_(window) {}
   ~WmWindowMusTestApi() {}
 
   void set_use_empty_minimum_size(bool value) {
     window_->use_empty_minimum_size_for_testing_ = true;
   }
 
  private:
+  static void SetDefaultUseEmptyMinimumSizeForTesting(bool value);
+
   WmWindowMus* window_;
 
   DISALLOW_COPY_AND_ASSIGN(WmWindowMusTestApi);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_BRIDGE_WM_WINDOW_MUS_TEST_API_H_